Transcript
US006141330A
United States Patent [19]
[11] Patent Number:
Akers
[45]
[54]
MULTIPLE ISDN AND POTS CARRIER
Inventor:
Date of Patent:
Francis I. Akers, San Mateo, Calif.
0 251 986 A2 0 251 986 A3
1/1988 1/1988
European Pat. Off. ....... .. H04Q 5/02 European Pat. Off. ....... .. H04Q 5/02
WO 96/29814
9/1996
European Pat‘ Off‘ '
[73] Assignee: GoDigital Networks Corporation,
OTHER PUBLICATIONS
Fremont, Calif. 21
I
I
“ISDN Basic Access Digital Subscriber Lines,” Bell Com munications Research, Technical Advisory, TA—TSY—000363, Issue 1, Mar. 1987.
A 1' N ‘I 08 717 475 pp 0 / ’
[22] Filed:
Sep. 20, 1996
“Universal Digital Channel (UDC) Requirements and Objectives 9 ” Bell Communications Research 9 Technical
7
[51]
Int. Cl.
[52] [58]
U..S. Cl. ........................................... .. 370/264, 370/535 Fleld 0f Search ................................... .. 370/263, 264,
................................................... .. H04L 12/16 _
Adviser y, TA_TSY_000398, Issue 1, Se p ' 1986'
“Making the Transition, Fiber Winds its Way home,” Te1e_ phony Integrating Voice and Data Communications, Feb~
370/265, 270, 271, 391, 532, 536, 537, 538’ 542’ 543’ 535; 379/2’ 191’ 199 [56]
1988_ “2B21Q, Line Code Tutorial,” MSAN—127, Mitel Semicon
References Cited
ductor Product News, Jan. 1987.
U S PATENT DOCUMENTS 3,660,609
Oct. 31, 2000
FOREIGN PATENT DOCUMENTS
SYSTEM
[75]
6,141,330
(List continued on next page.)
3,746,795
5/1972 Tremblay et al. ................... .. 179/16 F __ 179/16 F 7/1973 FitZsimons et al. ..
P rimary Examiner—chi H- Pham Assistant Examiner—KWang B. Yao
370/522
Carse et al. ..... ..
Attorney, Agent, or Firm—Limbach & Limbach L.L.P.;
4,730,311
3/1988
4,853,949 5,140,630 5,247,347
8/1989 Schorr et al. . ..... .. 379/2 8/1992 Fry e161. .... .. 379/179 9/1993 Litteral etal. .......................... .. 358/85
5,400,322
3/1995
5,410,343
4/1995 Coddington et al. .
5,420,886
5 /1995 Ohmori ___________ __
375 Q58
ing phone lines and HDSL chipsets While retaining plain old
5,436,895
7/1995 Matsumoto
370/391
telephone service (POTS) With full failsafe capability. TWo
5,440,335 5,448,635
8/1995 Beveridge ............................... .. 348/13 9/1995 Biehl et al. ........................... .. 379/399
Original ISDN Signals [4,5] at a rate of 160 kbps and one POTS Channel [10] digitized at 64 kbps are multiplexed by
574507486
9/1995 M?“ et al'
5’528’281
_____ __ 348/7
6/1996 Grady et a1‘ " 10/1996
[57]
ABSTRACT
Hunt et al. ............................ .. 370/468
High-speed digital transmission can be achieved With exist
379/399
a MIPCS card [6] of a signal provider
370/112
digital signal is transported over a tWisted cable pair [2]
""" " 348”
Which has an approximate maximum length of 16 kft based
5’459’729 10/1995 Bhven """"" " 5,566,301
Seong-Kun Oh
KoZ et al.
.. 709/250
.
.
The resulting .
.
575777115 11/1996 Deutsch et aL
379/399
on the current technology. At a receiving end, the signal is
5,596,604
1/1997 cio?i et a1_ _____ __
375/260
demultiplexed and regenerated by a subscriber’s MIPCS
5,598,413
1/1997 sansom et a1_
370/468
card
5,610,922 5,621,731 5,627,833
3/1997 Balatoni ...... .. 4/1997 Dale et al- 5/1997 Bliven ............. ..
370/468 370/257 370/464
the cable [2] to avoid dependence upon local poWer. The regenerated signals are transmitted over one POTS line [42] and [W0 ISDN Cables [89] to remote premises_ Both MIPCS
576577381
8/1997 HughesfHartogs
379/10Q12
cards have bypass relays for the POTS lines to ensure the
5’668’814
9/1997 Balatom """"" "
370/540
subscriber’s POTS access in the event of a local poWer
Outa e or electronic failure
5,682,385
10/1997 Garcia et al.
370/458
5,691,718
11/1997 Balatoni et al.
370/112
5,787,088
7/1998 Dagdeviren et al
5,815,505
9/1998 Mills ..................................... .. 370/522
g
31 Claims, 4 Drawing Sheets
ISDN ] I ISDN Slgnal 6 | N I MIPCS I Card
N 46,
Card \A
10
]
]
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|
l i
I 2:
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.
PSTN asap? ‘Signal I
VF
|
Signal
:
P '
:
]
31 I
I
N I
I
48V Power I Supply ]
II
|
|
i
[ _ _ _ _ _
:
|
: Tw'sted I
I
|
:
I
'
POTS PSTN Line I
I
:
Card
I
I‘ ___________ “I
|
4* I
5
'
370/493
]_ _______ "I
PSTN
The subscriber’s MIPCS card is line-powered via
[V7 MIPCS Card
ISDN CableI I | :
Remote
Networking Device
M54141, Device
e W01‘ mg
|
Telephone
_ _ __
IN Signal Provider
8
Signal Subscriber
6,141,330 Page 2 OTHER PUBLICATIONS
“Implementing an ISDN Architecture Using the ST—Bus,” MSAN—128, Mitel Semiconductor Product News, Mar.
Requirements and Objectives for Digital Main Line (DAML), Paci?c Bell, PUB L—780057—PB/NB, Issue 1, May 1989.
1987.
Article on “BT8960 Single—Chip 2B1Q Transceiver”, Mar.
Time Space Switching of 8, 16 or 32K Bps Channels Using the MT8980, MSAN—129, Mitel Semiconductor Product
ISDN—Network Interface Unit (I—NIU) Request for Quota
News, Apr. 1987. “Implementation Details of the MT8930 S/T Interface” MSAN—130, Mitel Semiconductor Product News, Oct. 1988.
“Digital Networks, Digital Sections and Digital Line Sys tems,” The International Telegraph and Telephone Consul tative Committee, ISBN 92—61—03351—2, Nov. 1988. “A Two—Wire Digital 0+2 Local—Line System for the Voice
Network,” British Telecommunications Headquarters, Speci?cation RC 7328, Apr. 1988.
1996.
tion RFQ #N96—NET—0049 Technical and Environmental
Requirements. US. Patent Application No. 08/701813, ?led Aug. 21, 1996. US. Patent Application No. 08/747,068, ?led Nov. 8, 1996. “ISDN Basic Access Digitial Subscriber Lines”, Technical Reference TR—TSY—000393, Bellcore Communications
Research (May 1988), “ISDN Basic Access Transport System Requirements”, Technical Advisory TA—TSY—000397, Bell Communica
tions Research (Oct. 1986).
6,141,330 1
2 One other approach is to more ef?ciently utiliZe existing
MULTIPLE ISDN AND POTS CARRIER SYSTEM
phone lines for high-speed digital transmissions. The phone
FIELD OF THE INVENTION
lines are made of tWisted copper pairs and are con?gured in a star-like architecture that is suitable for bi-directional
The ?eld of the invention relates generally to high speed digital communication. More particularly, the ?eld of the invention relates to transportation of tWo ISDN signals and
communications. The principal technology for placing a digital signal onto a copper pair that originally provided only analog dial tone is called integrated service digital netWork
one POTS signal over one tWisted cable pair from a front
(ISDN). ISDN Was developed in the 1980’s, When the
end and regeneration of the ISDN and POTS signals at a
state-of-the-art digital encoding technology resulted in the
remote end. 10
BACKGROUND OF THE INVENTION The recent groWth of the Internet has created both a tremendous demand for additional subscriber access to
standards as described in Bellcore documents TR-TSY
000393 and TR-TSY-000397. The basic transmission speed, called BRI for ISDN is 160 kilobits per second (kbps). This digital rate and its corresponding communication method are digital subscriber line (DSL). It is signi?cant that ISDN Was
public sWitched telephone netWorks (PSTN) and a demand
for additional bandWidth for the access. The former demand 15 designed speci?cally for a non-loaded telephone plant since
is being met by deploying additional analog access lines so
loading capacitors effectively attenuated high frequency
that modems can be used for the Internet access, and the
digital signals. The non-loaded cable plant reaches 18 kft but
latter demand is being met by deploying integrated service
only 85% of all subscribers on average. This results in a
digital netWork (ISDN) lines over tWisted cables. In the ?rst case, although Internet access is provided, it is not of sufficient bandWidth to provide the graphic-rich service Which typically is desired. In the latter case, a subscriber’s
problem With respect to reaching all subscribers desiring ISDN services. Since 1990, the development of micropro
20
cessors has signi?cantly improved the performance of com
munication chipsets. High bit rate subscriber line (HDSL)
main standard plain old telephone service (POTS) line is not
chipsets can run at 784 kbps or even 1 Mbps to transport one
converted to ISDN in order to maintain the subscriber’s
half of a T1/E1 digital loop carrier signal in an application
POTS access in the event of a local poWer outage or 25
called “Repeaterless Tl/El.” Other types of high speed
electronic system failure because the ISDN service is depen
communication technologies for the tWisted pairs, such as asymmetric DSL (ADSL), are emerging from labs but are still too expensive for Wide range applications. HDSL tech nology can be used to transport either one high speed signal
dent upon the residence poWer and proper function of the ISDN electronics. In both cases, the installation of an
additional copper-pair based access line is expensive and time consuming due to a general shortage of pre-existing installed cable pairs.
30
loWer bit signals is more cost effective than installing several
In the latter case, the ISDN installation on existing cable pairs is limited to about 70% of the installed base due to the manner in Which ISDN transport Was designed speci?cally
for non-loaded cable plants. The existing copper cable outside plant Was constructed in accordance With design
or several loWer speed signals through multiplexing and demultiplexing. Installing one high bit line for multiple
35
loWer bit lines. This approach Was explored by several inventors in the past. By Way of example, Carse et al., US. Pat. No. 4,730,311 describe a multiplexer for use in a telephone system in Which
requirements specifying that for local loops exceeding 13
a plurality of subscriber locations are connected to a central
kilo-ohms (k9), or approximately 18 kilo-feet (kft) Which is equivalent to 5,486 meters, loading coils or ?lter capacitors
of?ce by a single subscriber loop. Carse et al. focus on the
are added to remove voice frequencies shifted above 4
40
kilo-Hertz (kHZ) due to the loop resistance. The REA loop
design of the multiplexer rather than the entire communi cation system. Their technique applies generally to any methods of digital transmission, consequently the transmis
survey of 1986 indicates that for the US as a Whole,
sion rate is arbitrary. The subscribers are de?ned to be
approximately 85% of all loops are non-loaded. Since ISDN uses a digital signal operating at a center frequency of 40
locally poWered and backed-up With battery poWer. The
kHZ, it Will not transmit in the presence of a load coil. Bridged taps or branches attached to a primary cable run further reduce the reach of an ISDN signal, With the net
battery back-up can only last for a limited period of time in 45
the case of local poWer loss. For the design of the multiplexer, Carse et al. do not de?ne either a digital
interface or standard of loopback testing. Also, the con?gu
result being that only about 70% of all existing subscribers
ration of the central office is not described.
can have ISDN service added Without additional construc
Litteral et al., US. Pat. No. 5,247,347 and Coddington et al., US. Pat. No. 5,410,343 de?ne hoW to provide digital
tion expenses, as reported by Paci?c Bell in early 1996. Therefore, providing ubiquitous digital access for all tele phone subscribers is limited by both the number of pre
video signals from a video information provider to one or
existing cable pairs and limitations imposed by the design of the telephone outside plant.
multiplexers used in both systems mainly perform frequency domain multiplexing/demultiplexing Which is inherently
One solution is for the telephone company to simply
more of a plurality of subscriber premises. HoWever, the
55
only describe transport and encoding of speci?c video signals rather than generic digital signals. Bliven, US. Pat.
the telephone companies due to the long depreciation sched ule for these cables. It is generally recogniZed that a higher bandWidth medium, such as ?ber optic cable, is the ultimate solution for the digital access though the ?ber connectivity
60
No. 5,459,729 describes a method and apparatus for trans
mitting and receiving multiple telephone signals over a single tWisted pair. TWo conventional telephone signals are
precludes the lifeline access in the event of local poWer failures. While the technical and ?nancial issues related to
?ber installation are being Worked out, installing copper cables only consumes capital and delays the day for ?ber iZation.
disadvantageous With respect to time domain multiplexing/ demultiplexing. The poWer source of the multiplexers is not speci?ed. In addition, Litteral et al. and Coddington et al.
install more copper cables. In fact, record amounts of copper cables are being installed in response to the huge demand for added lines. But this is not a ?nancially viable alternative for
65
converted into one digital signal and then transported over a single tWisted pair at a rate of 160 kbps. Creating a multi plicity of telephone channels in this Way is suf?cient for analog POTS but is too loW to provide adequate Internet access.
6,141,330 3
4
Accordingly, it is a primary object of the present invention to provide a communication system that transports multiple
a local ISDN netWork. The ISDN and POTS signals are then
multiplexed by the MIPCS card 6, and the multiplexed signal is sent to a signal subscriber 3 over the tWisted cable
ISDN signals and a POTS channel over a single tWisted cable pair at a high bit rate. It is a further object of the invention to provide line poWering to a remote terminal to
pair 2. The MIPCS card 6 is poWered by a 48-Volt poWer supply 31. Since each of the ISDN signals has a rate of 160 kbps and a digitiZed POTS channel occupies 64 kbps, the tWisted cable pair 2 is required to provide a minimum speed of 384 kbps. The maximum length of the cable is limited by either the MIPCS system’s ability to transmit the poWering
avoid dependence upon local poWer and to provide for a metallic POTS access in the event of electronic failures. This invention is subsequently referred to as a “multiple ISDN and POTS carrier system” or abbreviated as “MIPCS.” 10
SUMMARY OF THE INVENTION
voltage, or the signal processing ability of the digital encod ing chip. For example, the BROOKTREE 8960 chip has an advertised reach of 16.5 kft. Both of these limitations are due
These and other objects and advantages are attained by connecting a signal provider to a signal subscriber through a tWisted cable pair. The maximum length of the cable is approximately 16 kft depending upon the Wire gauge, Which
15
offers roughly 1.2 kQ loop resistance, from the signal provider to the signal subscriber, back to the signal provider. The signal provider comprises one MIPCS card poWered by
variable but also controllable to some extent, depending on
the value of providing the digital service to the customer. In summary, one practical limit of the reach of the system is the loop resistance Which governs poWering as Well as signal. Given the state of the art in digital encoding, as exempli?ed by the BROOKTREE 8960 chip, 1.2 k9 is roughly a
a 48-Volt poWer supply. The MIPCS card connects tWo ISDN cards and one POTS line card to the tWisted cable pair. The ISDN cards provide a digital interface betWeen a PSTN and a local ISDN netWork at a transmission rate of 160 kbps.
The components of the MIPCS card comprise a transceiver, a digital interface module, a subscriber line interface (SLI) module, a bypass relay, and a utility microprocessor. The
practical limit, and this corresponds to approximately 16.5 25
transceiver uses a 2B1Q transport mechanism and operates at a minimum rate of 384 kbps. The digital interface module uses tWo ISDN U-interfaces. The bypass relay ensures the
kft on mixed 26 and 24 gauge cable plant. It is anticipated that the practical reach of the MIPCS system may increase as improvements are made in subsequently available digital
encoding chips Which replace the BROOKTREE 8960. Similarly, if the loop is comprised of 24 AWG Wire, the
subscriber’s POTS access in the event of a local poWer
outage or electronic failure. The utility microprocessor per forms loopback testing in accordance With the National ISDN Standards. The signal subscriber comprises a MIPCS card, one POTS line, and tWo ISDN cables. The MIPCS card connects the tWisted cable pair to the tWo ISDN cables and one POTS
to a combination of loop resistance, loop capacitance, and other signal attenuation and degrading in?uences. The reach of a digital system may be increased by removing bridged taps, or by reneWing cable splices, or by replacing cables having Water intrusion, so the system reach is not only
35
reach Would exceed 20 Kft. The signal subscriber 3 contains a MIPCS card 7, one POTS line 42, and tWo ISDN cables 8 and 9. The MIPCS card 7 is poWered via the tWisted cable pair 2. The amount of poWer Which needs to be transmitted does not exceed 80 Volts on either Wire in accordance With the US. safety
standards. Internationally, the safety requirement for line
line and is poWered via the tWisted cable pair. The compo
poWering voltage varies and can go as loW as 50 Volts on
nents of the MIPCS card contain a transceiver, a digital
each Wire. The digital signal transported over the tWisted cable pair is demultiplexed and regenerated into tWo indi
interface module, a SLI module, a bypass relay, and a utility microprocessor Which are characteriZed by the same struc ture as those of the MIPCS card of the signal provider. The tWo ISDN cables carry the signals to a single remote premise
vidual ISDN signals and one POTS channel. The regener
ated ISDN signals have the same signal quality and distance
or multiple remote premises Where networking devices (NTl’s) are located. The transmission rate of the cables is
160 kbps, and their maximum length is 18 kft. The SLI
45
module supports a POTS loop With a normal resistance of
interface module 10, a utility microprocessor 11, a trans
560 Ohms and provides ?ve ringer equivalents.
ceiver 12, a SLI module 44, and a frame processor 33, as shoWn in FIG. 2. The digital data interface module 10 uses tWo ISDN U-interfaces, such as Motorola MC145572. The utility microprocessor 11 such as Motorola M68HC05 fam
DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic diagram of a high bit communica
ily provides loopback testing in accordance With the
tion system With a single tWisted cable pair. FIG. 2 is a simpli?ed block diagram for the MIPCS cards illustrated in FIG. 1. FIG. 3 is a schematic diagram according to an embodi ment called of?ce-to-house. FIG. 4 is a schematic diagram according to an embodi
National ISDN Standards. The transceiver 12 uses a 2B1Q
55
DETAILED DESCRIPTION
digitiZed POTS signal to analog and provides all standard functionality, such as ringing, off-hook detection, caller identi?cation tones, and other features. The bypass relay 46
A schematic diagram of an aspect of the invention is shoWn in FIG. 1. A signal provider 1 comprises a MIPCS card 6 Which connects tWo ISDN cards 4 and 5 and a POTS card 10 to a ?rst end of a tWisted cable pair 2. The MIPCS
E1 or T1 signal on a PSTN into a 160-kbps ISDN signal on
transport mechanism and operates at a speed of at least 384 kbps. One of such transceivers is Bt8960 DSL Transceiver by BROOKTREE Corporation With a transmission rate of
416 kbps in full duplex mode. The SLI module 44 in the MIPCS card for the signal provider emulates a telephone set for signaling purposes and converts the analog POTS chan nel to a digital signal Which is fed to the frame processor; While the SL1 module for the signal subscriber converts the
ment called corporate-intranet.
card 6 is plugged into an equipment shelf, constituting a signal provider terminal. The ISDN cards 4 and 5 convert an
capability as the original ones, and they are sent to remote premises over the tWo ISDN cables 8 and 9. The POTS signal is sent to the remote premises over the POTS line 42. Each of the MIPCS cards 6 and 7 comprises a digital data
ensures the subscriber’s POTS access in the event of a 65
electronic failure or local poWer outage. A ?rst embodiment of the invention is an of?ce-to-house system, as illustrated in FIG. 3. A MIPCS card 7 is installed
6,141,330 5
6
on a pole, on a house, or in a cabinet. TWo customers 18 and 19 in a same house or tWo different houses each have one ISDN access, and one of them has a POTS access. They
ISDN cards interfaced to the public sWitched telephone netWork and uses tWo ISDN U-interfaces.
7. The system of claim 1 Wherein the subscriber line interface module is connected to said from processor, said
maybe kept in close proximity for maintenance purposes. Because the MIPCS card 7 regenerates high quality ISDN
utility microprocessor, and one POTS line extended from said POTS card interfaced to the public sWitched telephone netWork. 8. The system of claim 1 Wherein the utility micropro
signals, the tWo ISDN lines can be 18 kft long from the MIPCS card, but the POTS line is limited to a 130-Ohm loop or about 2-kft-long on standard 24 AWG Wire. A second embodiment of the invention is a corporate intranet system, as shoWn in FIG. 4. In this case, a corporate
10
9. The system of claim 1 Wherein the utility micropro
ISDN user needs ISDN accesses at a remote of?ce 22 Whose
cessor comprises a means for providing loopback testing in accordance With the National ISDN Standards.
location is not permanently ?xed or Which is Wired With only
one tWisted pair. The tWisted cable pair 2, normally used for POTS, is temporarily or permanently converted by adding a MIPCS card 6 in a business Wiring closet 32 and a MIPCS card 7 in the remote of?ce 22 to provide tWo ISDN
10. The system of claim 1 Wherein the bypass relay 15
connections, in addition to the original POTS channel. It Will be clear to one skilled in the art that the above
embodiments may be altered in many Ways Without depart ing from the scope of the invention. For example, more than
Accordingly, the scope of the invention should be deter What is claimed is:
connects said tWisted pair and the POTS line extended from said POTS card interfaced to the public sWitched telephone netWork. 11. The high bit communication system of claim 1 Wherein the signal subscriber comprises one MIPCS card, tWo ISDN cables having a ?rst end and a second end, and one POTS line having a ?rst end and a second end.
one tWisted cable pair can be used to transport more than tWo ISDN signals and more than one POTS channel.
mined by the-folloWing claims and their legal equivalents.
cessor connects said frame processor to said digital data interface module and said subscriber line interface module.
25
12. The system of claim 11 Wherein the MIPCS card connects the second end of the tWisted cable pair to the ?rst ends of the ISDN cables and POTS line. 13. The system of claim 11 Wherein the MIPCS card is
poWered via the tWisted cable pair, and the line voltage does
1. A high bit communication system, comprising: a) a single tWisted cable pair With line-poWering capabil
not exceed 160 Volts in total or 80 Volts per Wire in
accordance With the US safety standards. 14. The system of claim 11 Wherein the MIPCS card is poWered via the tWisted cable pair in accordance With the
ity; b) a signal provider con?gured to multiplex tWo ISDN signals and a POTS channel and to connect a public sWitched telephone netWork to a ?rst end of the tWisted cable pair having a transmission rate of at least 384
international safety standards, Which vary and can go as loW as 50 Volts on each Wire.
kbps, the signal provider including one MIPCS card Which connects tWo ISDN cards and one POTS line 35
15. The system of claim 11 Wherein the MIPCS card comprises a transceiver, a frame processor, a digital interface module, a subscriber line interface module, a utility
microprocessor, and a bypass relay.
card to the ?rst end of said tWisted cable pair, the MIPCS card including a transceiver, a frame processor, a digital interface module, a subscriber line interface
module, a utility microprocessor, and a bypass relay;
16. The system of claim 15 Wherein the digital interface module connects said frame processor, said utility microprocessor, and said ?rst ends of said tWo ISDN cables,
and
and uses tWo ISDN U-interfaces.
17. The system of claim 15 Wherein the subscriber line interface module is connected to said frame processor, said
c) a signal subscriber con?gured to demultiplex and regenerate said tWo ISDN signals and said POTS channel received via said tWisted cable pair at said
utility microprocessor, and the ?rst end of said POTS line.
18. The system of claim 15 Wherein the subscriber line transmission rate of at least 384 kbps and to connect a second end of the tWisted cable paW to remote pre 45 interface module supports a local loop of up to 530-Ohm
resistance With ?ve ringer equivalents. 19. The system of claim 15 Wherein the utility micropro
mises; Wherein said signal provider is con?gured to use a
cessor connects said frame processor to said digital data interface module and said subscriber line interface module.
2B1Q transport mechanism for transmitting signals at a minimum rate of 384 kbps.
2. The high bit communication system of claim 1 Wherein the tWisted cable pair is approximately 16 kft providing approximately 1.2 kQ maximum loop resistance, from the signal provider to the signal subscriber, back to the signal
provider. 3. The high bit communication system of claim 1 Wherein said POTS channel is by default mechanically available to said subscriber in the event of either a local poWer loss or
electronic failure. 4. The system of claim 1 Wherein the ISDN cards provide
digital interfaces betWeen a public sWitched telephone net Work and a local ISDN netWork With a transmission rate of
160 kbps. 5. The system of claim 1 Wherein the MIPCS card is poWered With a 48-Volt poWer supply. 6. The system of claim 1 Wherein the digital interface module is connected to said frame processor, said utility microprocessor, and tWo ISDN cables extended from said
55
20. The system of claim 15 Wherein the utility micropro cessor is adapted to provide for loopback testing in accor dance With the National ISDN Standards. 21. The system of claim 15 Wherein the bypass relay connects said tWisted pair and the ?rst end of said POTS line. 22. The system of claim 11 Wherein said ISDN cables and said POTS line connect the MIPCS card to remote premises. 23. The system of claim 11 Wherein the ISDN cables have a transmission rate of 160 kbps and a maximum length of 18 kft. 24. The system of claim 11 Wherein the POTS line has a
maximum length of 2 kft Which corresponds to a loop resistance of 130 Ohms.
25. A high bit communication system, comprising: a single tWisted cable pair; a signal provider con?gured to multiplex at least tWo ISDN signals and a POTS signal, each of said ISDN
6,141,330 8
7 signals having a transmission rate of 160 kbps and said POTS signal having a transmission rate of 64 kbps, Wherein said signal provider includes a ?rst transceiver,
29. A method of transmitting tWo ISDN signals and one
POTS signal, said method comprising the steps of: multiplexing at least tWo ISDN signals and a POTS
a ?rst frame processor, a digital interface module, a
signal, each of said ISDN signals having a transmission rate of 160 kbps and said POTS signal having a transmission rate of 64 kbps, and in accordance thereto,
subscriber line interface module, a utility microprocessor, and a bypass relay, said ?rst trans
ceiver con?gured to couple said single tWisted cable pair to said frame processor, and to transmit digital signals at a minimum rate of 384 kbps; and a signal subscriber con?gured to receive said multiplexed
generating a multiplexed signal, said generating step including the step of providing a transceiver, a frame 10
signal from said signal provider via said tWisted cable
interface module, a utility microprocessor, and a bypass
relay;
pair at said transmission rate of at least 384 kbps, said
signal subscriber further con?gured to demultiplex said multiplexed signal and to re-generate said tWo ISDN signals and said POTS signal at said transmission rates
processor, a digital interface module, a subscriber line
15
providing said multiplexed signal to a ?rst end of said tWisted cable pair at a tWisted cable pair transmission rate of at least 384 kbps using a 2B1Q transport
mechanism;
of 160 kbps and 64 kbps, respectively;
receiving said multiplexed signal from said signal pro
Wherein said signal provider is further con?gured to use a 2B1Q transport mechanism for transmitting signals at
vider via said tWisted cable pair at said transmission rate of at least 384 kbps; and
a minimum rate of 384 kbps.
26. The system of 25 Wherein said tWisted cable pair transmission rate is 416 kbps. 27. The system of claim 25 Wherein said signal subscriber
demultiplexing said multiplexed signal to re-generate said
includes a second transceiver and a second frame processor,
30. The method of claim 29 Wherein said tWisted cable
tWo ISDN signals and said POTS signal at said trans
mission rates of 160 kbps and 64 kbps, respectively.
said second transceiver con?gured to couple said single tWisted cable pair and said frame processor, and to transmit digital signals at a minimum rate of 384 kpbs. 28. The system of claim 25 Wherein the tWisted cable pair
is approximately 16 kft providing approximately 1.2 kQ maximum loop resistance, from the signal provider to the signal subscriber, back to the signal provider.
pair transmission rate is 416 kbps. 25
31. The method of claim 29 Where in the tWisted cable
pair provides approximately 1.2 kQ maximum loop resis tance from the signal provider to the signal subscriber back
to the signal provider. *
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